1. Field to Which Invention Relates
This invention relates to a chain of square ended valve bags, the method of making and filling the square ended valve bags and to a square ended valve bag included in the chain of square ended valve bags and removable therefrom by separating each successive bag from the chain of bags. More specifically, the invention is directed to a square ended valve bag wherein a patch or overlapped portion on the top end are partially sealed together from each seal side of the bag towards the opposite side of the bag, thereby defining valve means through which the bag may be filled from the top.
2. Description of the Prior Art
In prior bags of the square end type, the mouth of the bag has extended from one side wall to the other side wall. Other square ended bags which are also considered to be valve bags made from a film tube are Elwin David Jones, U.S. Pat. No. 3,548,722; E. D. Jones, U.S. Pat. No. 3,482,762; and John Warndell, U.S. Pat. No. 3,646,856. Jones U.S. Pat. No. 3,548,722 teaches a valve insert and a valve formed with the overlapping edges of film forming the top end of a bag. Jones U.S. Pat. No. 3,482,762 teaches the forming of a valve by constructing one of the gussetted end panels in two portions sealed together with their extremities such that they form a valve. Warndell U.S. Pat. No. 3,646,856 teaches the forming of a valve in the gussetted end by means of a valve patch secured around three sides of a slit in the gusset.